Should I skip the asymmetrical mousepad if I'm left-handed?

Yes. Get an ambidextrous (symmetrical) pad. Asymmetrical pads are designed for right-handed users—the cutout for the wrist, the angled edge, the extended surface on the right side—none of that works for a lefty. Most “gaming” or “ergonomic” mousepads with a wrist rest are molded for a right hand, forcing your wrist into a weird angle. An ambidextrous pad is just a rectangle or circle with no bias.